I didn't submit this to the bugtracker, since I'm not sure if it is a bug - but for some reason, the Platform Movement Object isn't working properly on recent updates of CF2.5. Each time I test my game or even make a full build, rather than falling, my player object just slowly drifts up. I tried on a different computer as well and still did the same thing.
I'd like if someone can also test the Object on their own copy of CF2.5 to see if it's doing the same thing and report on it. If not, it might just be how I set up the Events.